Name: Emulsions
Uploaded: 2019-07-19
Duration: 7 min 39 s
Description: Emulsions are one of the important classes of colloids that have a liquid phase dispersed in another liquid medium. Let’s explore some of their interesting p...

Question

What are the lyophilic and lyophobic colloids? How will you distinguish them?

Accepted Answer

Lyophilic and lyophobic colloids are the sols classified on the basis of affinity of dispersed phase for the dispersion medium. These can be defined as below:

(a)Lyophilic colloids are the colloidal solution in which the particles of the dispersed phase show great affinity towards the dispersion medium. When water act as a dispersed phase, the lyophilic colloids are referred to as hydrophilic colloids. The strong attractive force acting between the two phases makes stable solutions. These are reversible in nature. Gums, starch, and gelatine are examples of lyophilic solutions.

(b)Lyophobic colloids are the solution where the particles of the dispersed phase show no affinity towards the dispersion medium. These solutions are less stable and are not easily prepared. These can be obtained by adding a small amount of electrolyte or by heating. The solution prepared after precipitation cannot be reverted to colloidal solution and hence they are irreversible. Colloidal solutions of gold, silver, $Fe {(OH)}_{3}$ , ${As}_{2} S_{3}$ are lyophobic.

What are the lyophilic and lyophobic colloids? How will you distinguish them?

Important Questions on Surface Chemistry

Learn and Prepare for any exam you want !